Psoriasis is an unpleasant and incurable chronic skin disease, in which red scaly patches appear on the skin. It’s not contagious, but it can be painful, as well as causing psychological problems for sufferers.
Now scientists in Taiwan have shown that indigo, a dark blue plant-based powder used in traditional Chinese medicine, can help to relieve the condition. Indigo is sometimes given as a medicine for psoriasis in traditional medicine, but it can cause gut irritation and liver problems.
Writing in the Archives of Dermatology, Yin-Ku Lin and their team carried out a clinical trial of an indigo ointment in 42 patients with psoriasis whose condition was resistant to treatment. The patients tried the indigo ointment on one side of their body, then a non-medicated ointment to the other side, effectively acting as their own control. The researchers then assessed and photographed the patients' skin at the beginning of the study and again after two, four, six, eight, 10 and 12 weeks.
After 12 weeks of treatment, the areas treated with indigo ointment ha a significant improvement showed significant improvements, compared to the areas treated with the non-medicated cream. In fact, the indigo treatment led to an 81% improvement, whereas the non-indigo ointment only led to a 26% improvement.
Although only 34 patients made it all the way through to the end of the study, around three quarters of them found that the indigo ointment had completely or nearly completely cleared up their psoriasis, and none had any serious side effects.
This is still an early study though, and more research is needed to find a more potent extract of indigo for future studies. But this work shows that there’s certainly potential in indigo for treating this difficult disease.
Archives of Dermatology (2008);144:1457-1464.